This, finally, is Clarke's sticking point

The scene: somewhere in Africa. As far as the eye can see, grey- brown veldt shimmers in the heat. The heat is intense and the silence is utter. It is broken only once, by an aardwolf belching, many miles away. But not everything is quite as it should be. From the shadow of a lone baobab tree, its boughs heavy with mooching bustard, there comes the smell of cheap cigar smoke. And - look! - two feet protrude. And they are wearing Hush Puppies.

Kenneth Clarke (for it is he) has bewildered colleagues by his departure today for the dark continent. At home, the Conservative Party is driving itself into a frenzy about Europe, referendums and similar. Debates are planned, show-downs pencilled in. But the Chancellor, wobbling on the edge of resignation, will take no part. He has gone to commune with the meerkat and the secretary-bird.

Mr Clarke might reasonably say that had he waited until the Tory party was not in a frenzy over Europe, he would have been stuck in Britain for ever. Maybe. But he has left an aggressive message about his position. MPs have been waiting for him to deny that he might go. But as I write, no such denial has come.

Ministers have been expressing amazement at the notion that the Chancellor of the Exchequer might resign over something as nebulous and far-off as a plebiscite on monetary union - something that would only happen, after all, if a Tory Cabinet had first voted to abolish the pound. When Douglas Hurd first went round cabinet members asking about a referendum it was Michael Portillo, not Clarke, who was the most hostile. But really, there is no mystery.

What has happened is that the traditional pro-European view in the Tory party has been elbowed from the mainstream to the marginal in a remarkably short space of time. Clarke was once only one of a number of key ministers who were all basically integrationist. There was Hurd, Chris Patten, David Hunt, Malcolm Rifkind, William Waldegrave, Tristan Garel-Jones, Michael Heseltine. Oh yes, and that John Major, too.

Now they are all either gone, or have changed their views, or both. Heseltine doesn't seem to be going to the final ditch on the referendum issue. Among the other cabinet players, John Gummer isn't powerful enough really to help Clarke; while Stephen Dorrell, as a potential leadership candidate, has been busy demonstrating to right-wingers that he is acceptable.

So this is not really about the referendum. It is about Clarke's position in the Government and, inseparable from that, the status of the pro-Maastricht, strongly pro-EU Tories. They feel very isolated; as if their party is slipping away.

What has been happening to the Tories is a little like the Buchanan- v-Wall Street revolt that has shaken the US Republican Party. The pro- pound Conservatives are not protectionists, of course, but they are also fighting for familiarity and nationality against supranational forces. In both cases, it has been a popular uprising against the assumptions of the elite. And however blokey Clarke may seem, he has been firmly with the elite.

He may have already privately accepted that this stand disqualifies him from becoming leader of today's Tory party - however much he impresses them by his handling of the economy in general, and the Governor of the Bank of England in particular.

As the Man in the Treasury, Clarke has become increasingly self-confident. There has been no serious pressure from Number 10 for a tax-slashing pre- election splurge. If his nerve paid off, and he delivered a strong-looking economy at election time, he would normally have expected a huge personal dividend from the party.

But he will not pay the necessary price of pretending a modish anti-Europeanism. Other ministers, who have moved, shouldn't be surprised. As Philip Stephens, of the Financial Times, recalls in a new book, Politics and the Pound, Clarke took the decision not to temporise over a year ago, when he refused repeated requests from Major to tone down a speech denying that British membership of a single currency would have strong constitutional implications.

As Stephens writes, he even ignored the advice of his own political adviser, Tessa Keswick, who "was conscious that such a speech, offering not the slightest concession to the right of the party, could end permanently Clarke's hopes of eventually succeeding Major. Keswick was right, but the Chancellor would not be moved''.

He has always despised trimmers. His critics would say he has made a fetish of his own immovable consistency on this subject. Certainly, it has done him no good personally. Since Douglas Hurd left the Cabinet, shifting its centre of gravity, Clarke has undoubtedly felt lonely on the great issue of Europe; but it has been an isolation he has never flinched from.

Even then, that might not have mattered had Major handled it differently. At one level, this resolves itself into the oldest political question: who rules? Is the Cabinet a miniature Parliament, clustered around the Prime Minister; or is it a conclave of party barons, the grandest of whom have an effective veto over big changes in policy?

The answer must be, I think, that while the Prime Minister cannot carry change against a majority of the Cabinet, or an alliance of its grandest members, he is the only minister with a personal veto. No one else is so grand that he or she can hold back an idea to which most of the rest of the Cabinet is committed. In this case, Clarke-plus-Heseltine would have been enough to stop Major. But Clarke by himself may not be.

This leaves Cabinet ministers who find themselves in a minority on a serious issue with a stark choice: shut up, or go. When it comes to a real bust-up, there are few intermediate options.

So the only question left is whether Clarke thinks this is big enough to resign over. Were it only the referendum, that would indeed be a pretty bizarre view to take. But it isn't only the referendum. Clarke has been watching the European argument slip, and slip, and slip. We have become used to anti-Maastricht Tories saying that the European issue is "bigger than the party". Why should there not be some pro-Europeans who look at sceptics trying to close off British options and think the same thing?

I don't know if Clarke is there yet. But as a traditional pro-European, at some point he had to make a stand - to say: no more. It seems that the referendum is his chosen sticking-point; and he is sticking. Now he has 10 days away from the chatter of Westminster to sit under African skies, smoke cigars, and contemplate his choices. There, and here, the bustards are waiting.